OF ARTS AND SCIENCES. 253 



ovate to lanceolate bracts : flowers crowded, erect on very short pedi- 

 cels, fetid, greenish white; segments narrowly lanceolate, 1^ to 2 

 inches long : stamens half the length of the ovary : stigmas short, 

 sessile : fruit ovate, 2 or 3 inches long. — King's Rep. 5. 496, and 1. c. 

 47. T. Draconis, var. (?) arborescens, Torr. Pacif. R. Rep. 4. 147. 

 Southeastern California to S. Utah. 



h_ ^ ^_ Fruit capsular, septicidal and at length loculicidal at top, erect : seeds 

 thin, smooth, broadly margined, with entire albumen. Caudex none or 

 short, the panicle upon a tall scape. 



++ Leaves serrulate. 



7. Y. rupicola, Scheele. Acaulescent: leaves a foot or two long 

 by an inch or two wide, rigid, erect and pungent, smooth, deep green, 

 mostly oblique and undulate or twisted, with coarse reddish serratures : 

 scape 4 to 7 feet high, with long and narrow bract-like leaves : panicle 

 pyramidal, few-flowered ; bracts small : flowers greenish white ; seg- 

 ments ovate, sharply acuminate, \\ to 3 inches long: stamens straight, 

 equalling the ovary : style slender : capsule 6-sided, acute or beaked, 

 2 or 2\ inches long: seeds 34 to 4 lines broad. — Linnrea, 23. 143; 

 Engelm. 1. c. 48. T. lutescens, Carr. Western Texas. 



Var. rigida, Engelm. 1. c. Leaves pale and glaucous, not twisted, 

 carinate and often rough on the back, 8 to 12 inches long by 3 to 6 

 lines wide: capsule and seeds smaller. — Eastern New Mexico and 

 Northern Mexico. 



++ ++ Margin of the leaves filamentose. 



8. Y. angustifolia, Pursh. Leaves straight, very stiff and 

 pointed, usually 1 to 3 feet long by 3 to 6 lines wide, smooth : raceme 

 usually simple, nearly sessile, 1 to 4 feet long : flowers greenish white 

 or tinged with brown ; segments broadly ovate, an inch or two long : 

 stigmas green, shorter than the ovary : capsule 6-sided, 3 inches long, 

 half as wide : seeds broadly margined, 5 or 6 lines broad. — Sims, Bot. 

 Mag. t. 2236 ; Engelm. 1. c. 50. Dakota to New Mexico. 



Var. elata, Engelm. 1. c. Caudex 3 to 5 feet high, with numerous 

 glaucescent sometimes entire leaves ^ to 1| feet long: panicle oblong 

 or lanceolate, 3 or 4 feet long, as long as the peduncle : flowers white, 

 with narrower segments. — T. constricta, Buckl. Proc. Philad. Acad. 

 1862, 8 ? W. Texas to Utah and Northern Mexico. Various culti- 

 vated forms are probably referable to this (Baker, Gard. Chron. 

 1870, 1088). 



Var. mollis, Engelm. ]. c. Acaulescent: leaves softer and less 

 pungent, broadest (5 to 8 lines) in the middle : raceme or panicle \ to 



